How to set manual values for colorbar

Hi,

I want to create an colorbar with three colors (red, yellow, green) and I want to set the values for these colors.

For example:

Red = 100 to max value image

Yellow = 50-100

Green - 0-50

Can someone help me how to set the values for the colors manually.

Thanks!

[Alexandra Harkai]

This looks similar: Customize a colormap

Answer 1

[LauraLee Austin]

Let's assume the max value is 128 and your data is in a matrix X. I'm going to modify a demo file of earth to have values greater than 100 for this example.

m=128; % set max value
c=zeros(m,3); % start with all 0's
c(1:50,2)=1; %green
c(100:128,1)=1; %red
c(51:99,1)=1; %yellow
c(51:99,2)=1; %yellow
load earth
X=X*2;
image(X)
colormap(c)
colorbar